Cryogenic temperature controlled electrical biasing in-situ TEM sample platform

Transmission electron microscopy (TEM) is primary characterization method used to determine nanoscale features and local internal structure of materials. However, conventional TEM observations are usually performed under conditions different from a material’s actual working environment. If electrical biasing signals can be applied to the sample, then the relationship between structural properties and electronic properties can be investigated directly. Furthermore, if one at the same time subjects the sample to cryogenic temperature during imaging at high resolution, one can watch the material processes involved in structural and phase transformations as a result of electrical biasing at these low temperatures. However, there are also many technologically relevant materials systems (e.g. topological insulators, lithium batteries, etc.), which are air/moisture sensitive and prone to degrade when transported in unprotective environment in the TEM for characterization – requiring a dedicated air-free transfer hardware. Combining air-free transfer capability, temperature control using active liquid nitrogen (LN2) cooling, and with the application of electrical biasing signals will allow in-situ TEM studies of temperature induced transitions in material systems and allow real-time correlation between structure and electronic properties. Some of the important materials research areas that this capability will find application are in the study of battery materials and quantum materials such as superconductors and topological insulators that manifest their relevant behavior only at extremely low temperatures. In Phase I we developed the first prototype double-tilt, cryo-electrical biasing holder that allows the sample to be concurrently cooled to liquid nitrogen (LN2) temperature of -170 °C or heated to greater than 1000 °C during electrical biasing experiments. As many materials of interest are air- sensitive, in Phase II we will develop a double-tilt cryogenic biasing TEM holder with sample transfer shutter to transfer samples to the TEM in air-free conditions. We will bring this holder and the cryo biasing holder without a shutter, as well as all applicable support hardware to market for all different TEM platforms by the end of Phase II. The broader impact/commercial potential of this project will be the availability of in-situ TEM cooling electrical biasing sample holders (both with and without shutter) with heating. This will enable scientists to expand the knowledge of structure-property relationships in a new class of materials, specifically the relation between temperature and electronic properties, and will allow for the accelerated development of the next generation of electronic, quantum and energy storage materials and devices.